1. Field of the Invention
The present invention generally relates to photography and more particularly, to a photographic camera by which an object to be photographed can be taken in a pseudo focal length photographing mode as well as in a real focal length photographing mode. In the pseudo focal length photographing mode, a narrower scope for printing is specified than that in the real focal length photographing mode.
2. Description of the Prior Art
Conventionally, there have been proposed various kinds of the photographic cameras each of which is provided with the photographing lens having changeable focal length and accordingly, a large number of such photographic cameras have been on sale, as products. In the photographic cameras of such kinds, however, a changeable ratio in the focal length is restricted to approximately 1.6 to 1.8 times for the purpose of preventing the camera from being formed in a large size, simplifying a mechanism for changing the focal length, simplifying the design and production of the photographing lens and preventing the camera from being manufactured at a high cost. Consequently, users are not satisfied with the aforementioned changeable ratio, since the effect obtained by changing the focal length is not fully recognized.
On the other hand, the Japanese Patent Laid-open Publication (Tokkaisho) No. 54-26721 discloses a photographic camera having a real focal length photographing mode and a pseudo focal length photographing mode to thereby specify a scope for printing narrower than the scope in the real focal length photographing mode, in which camera an information for trimming, that is, a pseudo focal length photographing information related to the trimming process is recorded on a film used in the case where the pseudo focal length photographing mode is selected. A method called trimming in the field of photography is the method in which only a desired area of an image recorded on a frame is printed with enlargement. The camera of this kind is so constructed that the trimming information (information indicating that the pseudo focal length photographing mode is selected) is printed at the upper or lower portion of the film within a range other than the range to be photographed.
In this camera, although the focal length of the photographing lens can not be switched, it is capable of recording onto a film used, a signal signifying whether or not the print is requested with enlargement in a magnification larger than the ordinary magnification, through the trimming process with respect to the desired portion of the frame of the film which has been photographed. In the case where the film which has been photographed by such camera is printed, the print in compliance with a photographer's intention can be obtained in a manner that the magnification for enlargement is altered by reading the signals recorded on respective frames of the film. By employing such camera, it is capable of obtaining without any switching of the focal length of the photographing lens, through the trimming photography, i.e., the photography in the pseudo focal length photographing mode, the print similar to the print which is obtained through the photographing in the long focal length mode by the photographic camera with the changeable focal lengths. Accordingly, by the photographic camera enabling the trimming photography as disclosed in the aforementioned Publication, since it is not necessary to provide the mechanism for changing the focal length, unlike the focal length changeable camera, the photographic camera having a simple and compact construction can be manufactured advantageously at a low cost.
In the photographic camera that permits to photograph in the pseudo focal length photographing mode, however, since the enlargement is executed in the magnification larger than the ordinary magnification when the photographing in the pseudo focal length photographing mode has been executed, there is inevitably a limit for the possible magnification for enlargement in view of particle characteristics of the film, distance measuring performance of a distance measuring device and optical properties of the photographing lens, and consequently, the magnification is restricted to approximately 2 to 4 times at the utmost in the case where the magnification for enlargement is converted into the magnification in an equivalent focal length of the photographing lens.
With respect to the film on which the pseudo focal length photographing information is printed, since various kinds of data are formed as latent images thereof on the film or the portion of the film on which the pseudo focal length photographing information is printed is the portion on which various data are printed or notches are formed in a developing process, the developing system is subjected to an undesired influence. Furthermore, there has been such a possibility that the pseudo focal length photographing information is lost in the case where the notches are formed on the film in the developing process.
In addition, a correspondence can not be readily made between the print and a negative through respective views thereof, since the pseudo focal length photographing information is printed at the end portion other than the portion on which the image is formed. This is because only a part of the frame of the negative is printed and also, the information indicative of this fact is located at the position to be recognized with difficulty.
In the aforegoing focal length changeable camera, although there has been such an advantage that the photographing can be executed in a large magnification of the image in the case where the photographing lens is set to the longer side in focal length, a shortest distance up to the object for close-up photography is determined, in the photographic camera enabling an automatic adjustment of the focusing position in accordance with a result detected by an automatic focus detecting device, by the range of distance which can be measured by the automatic focus detecting device or by the range of the distance which can be adjusted by an automatic focus adjusting device, and as a result, no photographing can be executed in a magnification larger than that obtained by the above described camera.
Moreover, the focal length changeable camera is also known, for example, in the Japanese Utility Model Laid-Open Publication (Jikkaisho) Nos. 59-164037 and 59-164043, and in the Japanese Patent Laid-Open Publication (Tokkaisho) Nos. 59-191020 and 59-195601, or the like.